Moisture absorbent and selfventilating footwear



Jan. 20, 1959 v L. SACHS 2,859,253

MOISTURE ABSORBENT AND SELF-VENTILATING FOOTWEAR Filed April '7, 1955INVENTOR. LOUIS SACHS United Patent G MOISTURE ABSORBENT AND SELF-VENTILATING FOOTWEAR Louis Sachs, Baltimore, Md.

Application April 7, 1955, Serial No. 499,801

6 Claims. (Cl. 36-3) This invention relates to improvements in theconstruction of footwear and more particularly to improvements in thelining of boots, shoes and the like. This application constitutes acontinuation-in-part of my copending application, Serial No. 391,807,filed November 13, 1953 since abandoned.

One object of the present invention is the provision of an improved bootor shoe having a novel lining which functions to absorb moisture fromthe feet of the wearer so as to maintain the same in a substantially drycondition.

Another object of the present invention is the provision of a novel bootlining of the type described which is constructed so as to permitself-ventilation of the moisture laden air surrounding the feet of thewearer within the boots.

A further object of the present invention is the provision of a novelboot lining which is not only moisture absorbent and self-ventilating,but odor resistant, non-rotting and non-allergic as well.

These and other objects of the present invention will become moreapparent during the course of thefollowing detailed description andappended claims.

The invention may best be understood with reference to the accompanyingdrawings wherein illustrative embodiments are shown.

In the drawings:

Figure l is a perspective view partly broken away showing a bootembodying the principles of the present invention;

Figure 2 is a front elevational view of one portion of the boot liner ofthe presentinvention showing the same in a flat condition before beingapplied to the boot with parts broken away for clearer illustration;

Figure 3 is an enlarged cross-sectional view taken along the line 33 ofFigure 2;

Figure 3a is an enlarged cross-sectional view of a portion of Figure 3;

Figure 4 is a fragmentary rear elevational view of the boot liner;

Figure 5 is a fragmentary cross-sectional .view taken along the line 55of Figure 1;

Figure 6 is a top plan view .of an inner sole such as disclosed in myaforesaid application;

Figure 7 is a view similar to Figure 4 showing a modified form of bootliner; 7

Figure 8 is a cross-sectional view taken along the line 8-8 of Figure 7;and

Figure 8a is an enlarged cross-sectional view of a portion of Figure 8.

As disclosed in my copending application Serial No. 391,807, referred toabove, I have discovered that relatively thin compressed sheets of theinterior fibrous structure of the luffa plant may be molded to thecontour of inside surfacesof a boot orshoe, and when applied thereto,these sheets will effectively and rapidly absorb substantially all ofthe moisture present within .theshoe, thus maintaining the foot ndrycondition. I have further observed that when a shoe so equipped isremoved from the foot, such sheets will rapidly pass the moisture so absorbed into the air. I have therefore found that such thin sheets moldedand applied to the inside surfaces of boots and shoes, will be ofpronounced usefulness in maintaining the feet in dry and comfortablecondition. In the case of boots and shoes to be used in Arctic climates,the use of these sheets will prevent frost bite and freezing of thefeet, it being well known that the presence of moisture on the feet is aprimary cause of such casualties.

The luffa is a plant of the cucumber family whose fruit is of gourd-likeform having an interior structure of interlaced fibers which are lightbut strong. The pulp may be removed when soft, as by washing same fromthe overripe fruit, without damaging the interior fibrous structure. Thefibrous structure of the fruit comprises a tubular wall made up of anetwork of fibers, generally comprising an interior relatively coarselayer of interlaced fibers of generally parallel orientation and anexterior layer of finer, softer fibers of random orientation. When thepulp and core of the fruit are removed, the tubular wall may be cutlongitudinally and flattened into sheetlike form, and if desired, theinterior layer may be separated from the exterior layer to form separatesheets. These sheets are compressed by applying heavy pressure thereto.i

The plant having the fruit as referred to herein, has been defined inthe prior literature as being of the botanical family Cucurbitaceae,genus Luifa, and species Aculangula cylindrica or Aegyptiaca. It isfound in the Antilles and generally throughout the tropics, and in theOriental countries, including the Philippines and Japan. The fibrousstructure is of open-like character, with the fibers separated andinterlaced to provide a ventilated structure. When wet, the material maybe compressed to sheet form and molded to shapes as desired, and when itquickly dries, it will retain-the molded .shape. When compressed anddried, it tends to swell when moistened, but when thin sheets of thematerial are used as a lining for the interior .of a shoe upper, thereis not sufficient swelling to interfere with movements of the toes inthe shoe, considering the ample space which is provided above the toesin ordinary shoe and boot designs. The formed sheets of the material,used as described, may be impregnated with antiseptic or deodorizingmedicaments as desired.

With the above in mind, I have now found that when this material isutilized as a liner for a boot or shoe and provision is made toventilate the same during wear, it will substantially eliminate theproblems resulting from perspiration of the feet. The provision ofsuitable ventilation enables the moisture absorbent characteristics ofthe luffa material to be utilized to much greater advantage. That is,the luifa material not only serves to absorb a greater amount ofmoisture in a shorter period of time due to the movement of air, but inaddition, a portion of the moisture absorbed may be carried away by themoving air while the boot is being worn. The luffa material is ideallysuited to be utilized as a self-ventilating liner since its inherentopen interlaced structure permits air to freely pass through it.

Referring now to Figures l6 of the drawings, I have shown one embodimentof a liner 10 constructed in accordance with the principles-of thepresent invention as applied to a boot 12. In general, the liner 10comprises a sheet of compressed luifa 14, processed in the manner notedabove, having two layers of mesh material 16 and 17 on the finer surfacethereof and a plurality of lufia strips 18 on the coarser surfacethereof.

As shown in Figure 2, the liner 10 is preferably assembled in a fiatcondition before being secured within aseazss the boot. In assemblingthe liner, the compressed luifa sheet 14 is first cut out to form blanksconstituting a heel and ankle portion and a toe portion. The interiorrelatively coarse layer of fibers, while being interlaced,arefgenerallyoriented so that they extend in the same direction, and incutting out the heel and ankle portion, the sheet is positioned so thatthese fibers extend vertically. In a like manner, in cutting out the toeportion, the inner coarse fibers are made to extend generallyhorizontally. These two blanks may then be suitably secured together, asby stitching or the like, to form one-half of the entire liner, as shownin Figure 2.

- The strips 18 may be cut from a compressed sheet of luifa in such away that the interior coarse fibers extend longitudinally thereof. Thesestrips are then secured in spaced relation on the sheet 14 by anysuitable means, such as stitching or the like. Preferably, the strips 18are secured to the surface of sheet 14 which contains the interiorcoarse fiber layer; the strips secured to the heel and ankle portionbeing disposed generally vertically, with those secured to the toeportion being disposed generally horizontally. As shown in Figure 2, thestrips extend the entire length of the toe portion and are aligned withthe adjacent strips of the heel and ankle portion so that when the twoportions are together, the aligned strips, in effect, form continuousstrips.

The layers of mesh material 16 and 17 are preferably nylon and are cutto the shape of the combined heel and ankle and toe portions.Preferably, the two layers of nylon mesh material are suitably secured,as by stitching 19 or the like, to the surface of the sheet 14 oppositethe strips 18. Preferably, this surface constitutes the exterior finerlayer of fibers of the lufifa material.

Two such halves of the liner may then be secured within the boot in anysuitable manner. As shown in Figure l, the boot 12 comprises the usualsole 20 having the usual upper 22 secured thereto. The liner is afiixedto the upper by marginal leather strips 24 suitably secured to the upperand to the liner, as by stitching or the like. It will be understoodthat the liner may be compressed to the shape of the interior of theshoe before being secured and that other securing means may be utilizedif desired.

Of particular significance is the fact that the liner is secured to theupper with the strips 18 abutting the inner wall surface of the upper soas to space the lutfa sheet 14 therefrom. Thus, the strips divide thespace between the upper and the luifa sheet into a plurality of channels26 which extend from the sole of the boot upwardly to the open top edgethereof. In this regard, it will be noted that the marginal leatherstrip 24 at the top edge of the upper is secured thereto by verticallydisposed stitching extendng through the luflfa strips 18 so as to leavethe channels completely open to the air at the top as can be seen fromFigure 5.

It is preferred to utilize an inner sole liner 28 formed of a compressedsheet of lutfa material in the manner set forth in the aforesaidapplication. In brief, this inner sole liner consists of a compressedsheet of luifa material molded to the shape of the sole of the boot andadapted to removably rest thereon. As before, best results are achievedwhen the relatively soft outer fiber layer is exposed so as to contactthe foot of the wearer.

Referring now to Figures 7 and 8, there is shown a liner 30 of aslightly modified construction. In this embodiment, a compressed lulfasheet 32 and a plurality of strips 34 are formed out of a single pieceof luffa. It is preferable to form this integral sheet by cuttinggrooves out of the interior fiber layer of a dried longitudinally splitlufia plant, preferably where the interior ribs of the plant areconnected with the outer shell. In this manner, the exposed surface ofthe strips contain the relatively coarse fiber layer, and the fibersthereof are generally oriented in a longitudinal direction. The linermay then be built up with two layers of nylon .mesh 16 and '4 thereafterapplied to the interior of the boot in the manner previously described.This modified liner is especially advantageous for use in womens shoesdue to its relative thinness.

It can thus be seen that there has been provided by the presentinvention a liner which is both moisture absorbent and self-ventilatingthus assuring the maintenance of the wearers feet in a substantially dryand relatively cool condition. It will be understood that dry lufiamaterial has the property of absorbing moisture up to six or eight timesits own weight without dripping and is self-drying from a completelysaturated condition within four and five hours when exposed. The normalperspiration that would occur during use is, of course, considerablyless than this, and under normal conditions, the liner is self-drying ina matter of fifteen or twenty minutes after being removed from the foot.

When the boot of the present invention is being worn, the heat generatedby the foot warms the adjacent air, and since the liner 10 is of aporous or open network structure, the warm air passes through the linerand tends to rise through the channels 26 on the same principle as achimney. This movement of air enables the moisture in the air to morequickly come into contact with a greater area of the luffa material thuseffecting a more complete and faster moisture absorbency. Moreover,since the luffa material is somewhat exposed to the atmosphere, aportion of the moisture absorbed may be carried away by the moving airif conditions permit.

A significant feature of the present invention is that when the lufi'amaterial of the liner is fabricated in the manner indicated above, thenatural general orientation of the interlaced fibers tend to give properdirection to the flow of air. That is, since the general orientation ofthe fibers in the strips and the adjacent surface of the sheet run inthe same direction as the channels, a greater barrier is offered to theflow of air transversely across the strips than through the sheet orupwardly through the channels. In this manner, the luffa ma terialutilized not only provides the essential moisture absorbent properties,but also makes it possible to achieve a truly self-ventilating liner.The combination of moisture absorbency and self-ventilationsubstantially alleviate the problems heretofore experienced due toperspiration of the feet.

Another significant feature of the present invention is the fact thatthe liner is self-compensating to take care of extreme conditions. Asmentioned above, lufia expands as it absorbs moisture, but the expansionis not sufiicient to cause discomfort during wear. This expansion,however, operates in the present invention to achieve a greater amountof ventilation just at the time when such greater ventilation is'mostneeded, namely, when a greatdeal of moisture is being given off by thefeet. Stated differently, the more moisture absorbed, the moreventilation obtained. This is possible due to the expansion of luifamaterial particularly the strips, thus making the channels deeper andpermitting a greater amount of air to move.

I am aware that it has been proposed to provide boots and shoes with anintegral liner of ribbed knit material, such as cotton, wool or thelike, and that such liners achieve a somewhat limited degree ofventilation. However, such a liner constitutes nothing more than a mereribbed hose such as are in common use. It is well known, that the ribsof ribbed hose are primarily decorative and do not achieve anysubstantial ventilating effect} fresh air from the exterior. The reasonthat the inflain this system is very necessary is because in the passageof the warm air, moisture is absorbed from it. What is more, any humidair which enters the shoe from the exterior at its upper edge, is driedbefore it reaches the foot. Moreover, the moisture removed from humidair is taken care of by the upper portion of the lining, above theankle, while the moisture which originates from the foot is absorbed bythe part of the lining below the level of the ankle. Furthermore, due tosweat absorption, rapid evaporation by efiicient ventilation preventsdeposit of and retention of sweat odor. The use of wool as a lining,though it absorbs some sweat, retains it. It is organic material. Theacids and salts excreted in sweat becomes fixed in wool because of itsorganic structure and thus lead to rotting. On the other hand, lufifa isa cellulose, and therefore is resistant to products of sweating whichare absorbed thereby. Thus the present liner is also non-rotting andnon-allergic.

The use of two layers of nylon mesh serves to protect the interlacedfibers of the luifa material from being accidently separated and furtherserves to provide a smooth even surface which contacts the foot. Whilethe luffa fibers are somewhat stifi when completely dry, after a shortperiod of use, for example, fifteen minutes or more, the fibers softenand present a very pleasing and comfortable contact with the foot.

The use of the removable inner sole liner has the advantage that ifwater should seep into the shoes, the saturated inner sole liner may beremoved and replaced by a dry one. The completely saturated inner soleliner will then dry in a matter of three or four hours after beingremoved. Moreover, it will be appreciated that the liner of the presentinvention will likewise quickly dry from its normal relativelyunsaturated condition after removal following normal use, in a matter offifteen or twenty minutes. While I have described herein the utilizationof lufI'a as the preferred material for the boot liner because of itsproperties which are particularly suited to achieve the desiredfunctions, it will be understood that other materials, both natural andsynthetic, having properties approximating those of, luifa may beutilized to achieve somewhat the same results.

It will also be understood that the terms boots and shoes as herein usedare synonymous and comprehend within their meaning footwear in general,such as overshoes and the like. The forms of the invention herewithshown and described are to be taken as the preferred embodiments of thesame, and it will be apparent that changes may be made without departingfrom the spirit of the invention or the scope of the appended claims.

I claim:

1. In a shoe having a sole and an upper secured thereto, a liner forsaid upper including a porous inner sheet and a plurality of strips ofthe natural interlaced fibers of the lufia plant interposed between saidsheet and said upper, said strips extending in a direction toward theopen top edge of said upper and being spaced apart transversely to formchannels therebetween, said channels providing for the flow of warm airfrom the foot of the wearer upwardly therethorugh to thereby ventilatethe shoes, said luffa strips being operable to expand in accordance withthe amount of moisture absorbed thereby so as to increase the depth ofsaid channels and hence permit a greater air flow.

2. In a shoe having a sole and an upper secured thereto, a liner forsaid upper comprising a thin compressed sheet of the natural interlacedfibers of the luifa plant, thin strips interposed between the inner wallsurface of the upper and the outer wall surface of said compressed sheetso as to space the latter from the former, said strips being spacedapart and extending in a direction toward the top edge of said upper soas to divide the space between said sheet and upper into channels whichserve to ventilate the shoe and a mesh material adjacent the inner wallsurface of said sheet.

3. In a shoe having a sole and an upper secured thereto, a liner forsaid upper comprising a thin compressed sheet of the natural interlacedfibers of the lutfa plant having compressed luffa strips extending fromthe outer surface thereof, means for securing said sheet to the interiorof said upper with said strips engaging the inner wall surface thereofso as to maintain said sheet in closely spaced relation thereto, saidstrips being spaced apart from each other and arranged to extend towardthe top edge of said upper so as to provide channels which serve toventilate the shoe.

4. A shoe as defined in claim 3 wherein said strips form an integralpart of said lufia sheet.

5. A shoe as defined in claim 3 wherein said strips are separatelyformed and are secured to said lufia sheet.

6. In a shoe as defined in claim 2 said strips of the natural interlacedfibers of the luffa plant including a layer of relatively coarse fibersgenerally oriented in a direction parallel with the longitudinal extentof said strips.

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